18 



POLYGONACE.E. 



Eriogonum. 



Segments of perianth very unequal, the outer broad and subcordate : 

 cespitose perennials : inflorescence capitate or cymose-um- 

 bellate. 

 D'insely cespitose : leaves round or oblong : head solitary, rarely 



cyniose. 

 Caudex more diffuse : leaves oblanceolate, acute : umbel 3-rayed, 

 sparingly divided. 

 Segments similar, nearly equal, narrow at base. 



Perennials with short-branched caudex and naked |)eduncles : 

 bracts small : heads or fascicles solitary, or few in a long- 

 jointed cymose panicle (involucres sometimes solitary). 

 Dwarf, densely cespitose : head solitary : leaves small, linear- 

 oblong. 

 Peduncles mostly tall and stout ; caudex less branched. 



Heads large and dense, 1 or few : peduncle very stout, not 



fistulous ; tomentose. 

 Heads smaller, more numerous : leaves at least tomentose : 



peduncles more slender, fistulous. 

 Leaves large, villous : peduncles tall, iistulous, smooth. 

 "Woody branched perennials : stems very leafy : leaves fascicled 

 and bracts mostly foliaceous : heads more or less closely 

 cymose-umbellate. 

 Flowers villous : leaves round to oblong, obtuse : bracts sliort : 



heads few and open. 

 Flowers glabrous : leaves ovate to oblong, acute : bracts con- 

 spicuous : heads few, close. 

 Leaves narrowly oblanceolate, acute : umbel short and cymose, 

 often much contracted or capitate. 

 Involucres solitary (terminal and alar) in a repeatedly divided 

 corymb-like cyme : bracts mostly small : leaves not fascicled. 

 Perennial and woody. 

 Low and diffuse, slender : leaves oblanceolate to linear : um- 

 bel .short. 

 Stouter, more rigid, densely tomentose : leaves larger and 

 broader : umbel broadly cymose. 

 Annual : leaves mostly rosulate at base. 



Floccose-woolly throughout : leaves oblanceolate : involucres 



2 lines long. 

 Glabrous above : leaves rounded, small : involucres a line 



long : flowers minute. 

 Hirsute : leaves rounded : involucres glandular. 

 Involucres solitary along the often virgate branches of a naked 

 dichotomous panicle : bracts mostly small. 

 White-tonientose perennials : panicle sparingly branched, usually 

 virgate : involucre tomentose, teeth not margined. 

 Much branched at base : leaves oblanceolate, acute, often fas- 

 cicled : bracts small, triangular. 

 Sparingly branched at base : leaves rounded : bracts larger, 



subfoliaceous : branches short. 

 Sparingly branched : leaves lanceolate to ovate : involucres 

 larger (3 lines long), distant on the few elongated 

 branches. 

 Woody perennials : panicle diffuse with short rigid branchlets : 

 involucres short, teeth more or less margined. 

 Glabrate above, divaricately branched, the branchlets sub- 



spinescent : involucres few, distant, campanulate. 

 Tomentose, taller : branchlets very short-jointed : involucres 

 narrowly turbinate. 

 Annuals : leaves rosulate at base. 



Tomentose throughout : branches virgate, few : involucres 

 narrow, 2 lines long. 

 Leaves oblanceolate : branches elongated : flowers glabrous. 

 Leaves rounded : more diffuse : flowers villous. 

 More slender and diffuse : involucres smaller. 



Leaves rounded : rather diffuse, often glabrous : involucres 

 narrow, IJ lines long. 



E. OVALIFOLIUM< 

 E. DICIIOTOMUM. 



E. CINEREUM. 

 E. PARA'IFOLIUM. 

 E. FASCICULATUM. 



